填充剂对氢化丁腈橡胶阻尼性能的影响

通过胶料的应力-应变性能和动态力学(DMTA)性能研究了不同填充剂对氢化丁腈橡胶(HNBR)阻尼性能的影响,并从填充剂微观结构及阻尼机理方面进行了分析讨论。实验结果表明,在所考察的填充剂范围内,填充石墨的HNBR阻尼性能最好,云母次之。石墨和云母在微观形态上均属于典型的片状结构,其良好的阻尼性能与这种片状结构有一定关系。石墨填充量增大后,胶料的弹性模量和损耗模量在整个温度范围内均有一定程度的上升,阻尼系数tanδ和阻尼峰宽Δ0.3减小,玻璃化转变温度Tg变化不大。     

高阻尼橡胶的动态压缩性能及其应变率相关的本构模型

为研究高阻尼橡胶的动态压缩性能及其应变率相关的本构模型,应用分离式Hopkinson压杆装置对高阻尼橡胶试样进行冲击压缩试验,获得了不同应变率下的应力-应变曲线。结果表明,高阻尼橡胶体现了明显的超弹性特征,在500/s到5 200/s的大应变率范围内,高阻尼橡胶具有明显的应变率相关性,相同应变条件下,应变率越高,应力值越大。考察几种常见超弹性本构模型对试验数据的拟合情况,并选取拟合最优的本构模型,拟合结果与试验结果非常吻合,研究结果为高阻尼橡胶在抗爆炸、抗冲击领域的进一步研究奠定了基础。     

高阻尼硅橡胶的研制

以不同阻尼剂分别对硅橡胶主链和填料表面进行改性的途径制备了阻尼硅橡胶,分别通过DMTA和应力应变法对制备的阻尼硅橡胶进行了研究,结果表明：采用阻尼剂DA-1/DA-3=15/5并用的配方,硅橡胶的阻尼性能最优,综合性能最好。硅橡胶的蠕变性能随着阻尼剂DA-1比例的增加而改善。     

纳米硅酸盐与芳纶微米短纤维共补强HNBR复合材料的结构与性能

采用原位改性针状硅酸盐(FS)和芳纶短切纤维(DCAF)与氢化丁腈橡胶(HNBR)机械共混制备HNBR/DCAF/FS复合材料,研究DCAF用量、长度和FS用量对复合材料结构与性能的影响.结果表明,加入DCAF能显著提高复合材料小应变下的定伸应力和压缩模量,增大DCAF长度和用量有利于改善复合材料的拉伸性能及其各向异性;加入FS能明显改善复合材料的拉伸应力-应变特性,提高复合材料的压缩模量.     

交联密度对HNBR/聚甲基丙烯酸正丁酯IPN阻尼性能的影响

用序列法制备氢化丁腈橡胶(HNBR)/聚甲基丙烯酸正丁酯(PnBMA)互穿聚合物网络(IPN)材料,通过改变两网络的硫化剂用量得到不同交联密度的HNBR/PnBMA IPN。采用动态粘弹谱仪测试IPN的阻尼性能,结果表明HNBR/PnBMA IPN材料的阻尼特性与交联密度密切相关。随着第一网络交联密度的增加,阻尼曲线逐渐由双峰转变为单峰,阻尼峰宽降低。第二网络交联密度的增加使阻尼曲线整体下降,双峰形态不变。通过改变两网络的交联密度可调整阻尼峰的位置、宽度及阻尼峰值。     

橡胶材料循环加载的本构行为及数值拟合

使用电子万能材料试验机对炭黑填充的橡胶材料进行单轴循环加载,对稳定后的应力-应变曲线进行数值拟合。对加载段的应力-应变曲线采用Marlow,Arruda Boyce,Van der Waals和Yeoh等超弹性本构模型进行描述,对卸载段的应力-应变曲线采用Mullins模型,即应力软化模型进行描述,对永久变形行为采用塑性变形模型进行描述,并使用反分析方法确定Mullins方程的参数。结果表明,Marlow超弹性模型对加载段的应力-应变曲线拟合效果最好,Mullins模型可较好地描述大应变时卸载段的应力-应变曲线,但无法拟合出材料的永久变形行为;将Marlow超弹性本构模型、Mullins模型以及塑性变形理论相结合,可以精确地描述橡胶材料的循环加载与卸载条件下的应力应变行为。     

填充橡胶材料循环加载的本构行为及数值拟合

使用电子万能材料试验机对炭黑填充的橡胶材料进行单轴循环加载,对稳定后的应力-应变曲线进行数值拟合。对加载段的应力-应变曲线采用Marlow,Arruda Boyce,Van der Waals和Yeoh等超弹性本构模型进行描述,对卸载段的应力-应变曲线采用Mullins模型,即应力软化模型进行描述,对永久变形行为采用塑性变形模型进行描述,并使用反分析方法确定Mullins方程的参数。结果表明,Marlow超弹性模型对加载段的应力-应变曲线拟合效果最好,Mullins模型可较好地描述大应变时卸载段的应力-应变曲线,但无法拟合出材料的永久变形行为;将Marlow超弹性本构模型、Mullins模型以及塑性变形理论相结合,可以精确地描述橡胶材料的循环加载与卸载条件下的应力应变行为。     

硅酸盐纳米纤维/氢化丁腈橡胶复合材料的性能

研究了热处理时间、偶联剂类型及用量和针状硅酸盐(FS)对硅酸盐纳米纤维/氢化丁腈橡胶(HNBR)复合材料性能的影响。结果表明,微米颗粒的FS在HNBR中能够被解离成纳米纤维,并具有优良的增强效果。FS/HNBR复合材料具有短纤维增强橡胶复合材料的应力-应变特性和各向异性,硅烷偶联剂的加入和热处理能够提高复合材料的力学性能。热处理10min、FS用量为50质量份、偶联剂选用KH-570且其用量为2质量份时复合材料的力学性能较好。     

ECC三轴压缩特性试验研究

为探究纤维增强水泥基复合材料(ECC)在复杂应力状态下的受压特性,通过常规三轴压缩试验得到了不同围压下的ECC应力-应变曲线,分析了ECC的强度特性、变形规律以及破坏模式.试验结果表明:PVA纤维的掺入、施加围压能够有效约束ECC的径向变形并提高其韧性,且ECC的轴向峰值抗压强度和峰值应变随围压的提高而增大.ECC的三轴受压变形过程表现为弹性变形-应变硬化-应变软化三阶段,且围压越大,应力-应变曲线的软化段变化越缓和.在三轴受压状态下,ECC的主压应力、轴向峰值应变与围压有较好的线性相关性.     

硅酸盐纳米短纤维补强HNBR复合材料的性能研究

将原位改性针状硅酸盐（FS）与氢化丁腈橡胶（HNBR）机械共混制备FS／HNBR复合材料，研究FS的干燥、改性剂种类与用量对复合材料物理性能的影响。试验结果表明，改性FS在HNBR中分散良好，复合材料具有短纤维补强橡胶的应力-应变特性和明显的各向异性；FS的加入可显著提高复合材料的100％定伸应力、拉伸强度和压缩模量；当偶联剂KH-570用量为4～6份时，复合材料的物理性能最佳；干燥FS补强的复合材料具有更好的拉伸性能并可在高温下仍然保持良好的压缩性能。     

氢化丁腈橡胶／超细全硫化粉末丁腈橡胶共混物的结构与性能研究

采用熔融共混工艺制备了氢化丁腈橡胶（HNBR）／超细全硫化粉末丁腈橡胶（UFPNBR）共混物,研究了共混物相态结构、动态力学性能、力学性能及老化性能,并与HNBR／NBR共混物作了对比。透射电镜观察表明：在HNBR／UFPNBR体系中,HNBR容易形成连续相,UFPNBR为分散相;在HNBR／NBR体系中容易形成双连续相结构。DMA动态力学性能分析表明：2种共混物都只有一个tanδ峰,且相容性较好。HNBR／UFPNBR共混物在玻璃化转变区的tanδ峰值逐渐降低,而HNBR／NBR体系的tanδ峰值先减小后增大。加入适量的UFPNBR能降低HNBR／UFPNBR共混物的压缩永久变形;与常规共混胶相比,HNBR／UFPNBR具有低脆性温度和良好的耐老化性能,但力学性能略低。     

Unlubricated rolling wear of HNBR/FKM/MWCNT compounds against steel

The rolling friction and wear of the compounds of peroxide‐cured hydrogenated acrylonitrile/butadiene rubber (HNBR) and fluororubber (FKM) (HNBR‐FKM) with and without multiwalled carbon nanotube (MWCNT) contents were studied against steel in orbital rolling ball (steel)‐on‐plate (rubber) test rig (Orbital‐RBOP). The phase structure of the rubber compounds in the presence and absence of MWCNT was studied by dynamic mechanical thermal analysis (DMTA), transmission electron and atomic force microscopy (TEM and AFM, respectively). It was established that HNBR formed the matrix in which micron‐scaled FKM domains were dispersed. MWCNT was preferentially embedded in the HNBR. The network‐related and surface tension properties of the rubber compounds were derived from DMTA tests and contact angle measurements, respectively. The Martens hardness of the rubbers was also measured. The coefficient of friction (COF) and specific wear rate (W_s) were determined in Orbital‐RBOP. Blending of HNBR with FKM increased the COF slightly and decreased the specific wear rate prominently when compared with pure HNBR. Additional MWCNT reinforcement (10 parts per hundred part rubber, phr) of the HNBR and HNBR‐FKM further increased the COF and at the same time improved the wear resistance. The wear mechanisms were concluded by inspecting the worn surfaces in scanning electron microscope (SEM) and discussed as a function of FKM and MWCNT modifications. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Optimized process for the inclusion of carbon nanotubes in elastomers with improved thermal and mechanical properties

The effects of addition of reinforcing carbon nanotubes (CNTs) into hydrogenated nitrile–butadiene rubber (HNBR) matrix on the mechanical, dynamic viscoelastic, and permeability properties were studied in this investigation. Different techniques of incorporating nanotubes in HNBR were investigated in this research. The techniques considered were more suitable for industrial preparation of rubber composites. The nanotubes were modified with different surfactants and dispersion agents to improve the compatibility and adhesion of nanotubes on the HNBR matrix. The effects of the surface modification of the nanotubes on various properties were examined in detail. The amount of CNTs was varied from 2.5 to 10 phr in different formulations prepared to identify the optimum CNT levels. A detailed analysis was made to investigate the morphological structure and mechanical behavior at room temperature. The viscoelastic behavior of the nanotube filler elastomer was studied by dynamic mechanical thermal analysis (DMTA). Morphological analysis indicated a very good dispersion of the CNTs for a low nanotube loading of 3.5 phr. A significant improvement in the mechanical properties was observed with the addition of nanotubes. DMTA studies revealed an increase in the storage modulus and a reduction in the glass‐transition temperature after the incorporation of the nanotubes. Further, the HNBR/CNT nanocomposites were subjected to permeability studies. The studies showed a significant reduction in the permeability of nitrogen gas. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Free volume and damping in a miscible high performance polymer blend: Positron annihilation lifetime and dynamic mechanical thermal analysis studies

High performance polymer blend of poly(ether ether ketone) (PEEK) and poly(ether imide) (PEI) was examined for their free volume behavior at different compositions of PEI using positron annihilation lifetime spectroscopy (PALS). The damping property of the blend was studied using tan‐δ obtained from dynamic mechanical thermal analysis (DMTA). The dependence of tan‐δ on temperature revealed that the blend is miscible in all compositions, in agreement with earlier studies. The tan‐δ peak height is found to increase with increase in free volume fraction for the entire blend composition signifying that the free volume plays an imperative role in understanding the damping property. Using DMTA, master curves were obtained at a reference temperature T₀ by applying the time‐temperature‐superposition (TTS) using Williams‐Landel‐Ferry (WLF) relationship. From the shift factor a_T, the WLF coefficients and were evaluated, using which the free volume fraction was found. Both PALS and DMTA methods were found to give similar results for the dependence of free volume for various PEI contents studied in this blend. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 42961.     

氢化丁腈橡胶的开发研究

阐述了由丁腈橡胶制备氢化丁腈橡胶的研究工艺 ,给出了最佳工艺参数 ,考察了催化剂的活性及选择性 ,测试了氢化丁腈橡胶的IR谱图及分子量和分子量分布 ,评价了氢化丁腈橡胶的物理性能。     

BIPB硫化氢化丁腈橡胶性能的研究

研究了双叔丁基过氧化异丙基苯(BIPB) 硫化剂用量对氢化丁腈橡胶混炼胶硫化特性及硫化胶力学性能、耐热性能、耐油性能及压缩永久变形性能的影响。结果表明：随着BIPB用量的增加,混炼胶的焦烧时间t10和正硫化时间t90均逐渐减小,交联效率提高;硫化胶的物理机械性能、耐热性能、耐油性能和压缩永久变形性能均逐渐提高。当BIPB用量为4份时,硫化胶的综合性能达到最优。     

氢化丁腈橡胶/有机蒙脱土纳米复合材料的性能

采用熔体插层法制备了氢化丁腈橡胶/有机蒙脱土纳米复合材料,采用透射电镜和X射线衍射仪对复合材料的结构进行了表征,并研究了复合材料的应力应变行为、耐老化性能、耐溶剂性能和动态力学性能。实验结果表明:制备了一种插层型纳米复合材料,复合材料的耐老化性能和耐溶剂性能良好,并且随蒙脱土含量的增大而增加;动态黏弹谱(DMA)测试显示,纳米复合材料的玻璃化转变温度升高,且具有较低的滚动阻力,复合材料的动态力学性能优良。